These days, modern medical imaging systems such as, for example, magnetic resonance systems, computed tomography scanners, PET or SPECT systems, ultrasound equipment, etc. are able to supply very large amounts of image data at a high resolution from measured values. A challenge for improving the application of such imaging systems and the results obtained thereby therefore also consists of processing the large number of measured values and outputting the latter for a diagnosis and/or intervention planning such that the person diagnosing or the planner can recognize all relevant information.
Computed tomography has established itself as an imaging method in the medical sector. This method is based on emitting X-ray radiation through an examination object, e.g. through a human body, in which the location of the emission of the X-ray radiation, i.e. an X-ray source for example, is rotated around the examination object. A sensor apparatus on the same orbit with respect to the examination object is rotated opposite to the location of the emission of the X-ray radiation, and so the sensor apparatus registers the X-ray radiation penetrating the examination object. This results in measured values, for example in the form of raw image data or measured values derived from analyzing raw image data or processed raw image data, from which three-dimensional image data records can be generated by way of an image post-processing method. This means that the image data records represent and image the spatial structure of an examination region, i.e. a tissue region, for example.
In a development, a plurality of three-dimensional image data records of the same examination region, which were recorded with a time offset with respect to one another, can be combined in a sequence of steps, and so this results in a four-dimensional image data record that illustrates the development of an examination region over time. Thus, this is a so-called multi-phase three-dimensional data record, which is also referred to as a “movie”.
By way of example, such four-dimensional data records are used for imaging the heart, more particularly the myocardium, that is to say the heart muscle, wherein the procedure data can for example illustrate the cyclical change in the wall thickness and the cyclical wall movement, as well as the blood supply of the heart. By way of example, this allows the detection of pathological wall-movement disorders, which can for example be caused by a dangerous stenosis of a coronary artery.
A problem in cardiac imaging with the aid of three- or four-dimensional image data records is that pathological structures can only be recognized reliably if a multiplicity of aspects, such as for example the wall thickness, the cyclical variation thereof over time, the wall movement and the blood supply, are taken into account. This requires much specialist knowledge and much experience of the operator during the evaluation of the measured values.
In order to diagnose pathological wall-movement disorders, specialists still have to consider independently of one another all parameters in connection with the wall movement and further parameters of the function of the heart. This is connected to higher risks and moreover this is connected to significant time expenditure. Finally, the dependence on the evaluating person leads to lower reproducibility of the examinations. This is problematic particularly if comparison measurements are to be performed in order to follow the temporal profile of the change of tissue structures or the reaction thereof to certain therapeutic measures. Likewise, cross-comparison studies, in which the evaluation results from different patients or subjects are intended to be compared, only have a diagnostic value of limited reliability, should they even be possible.